UPDATED ON 1/22/2009Nielsen reports that from 10am to 5pm ET, an average 37,793,008 tuned into the ceremony, swearing in, speech and coverage of the Inauguration. That’s the second-most ever, slightly below the 41,800,260 who watched Reagan’s nomination in January 1981.

Keep in mind that the number does not include any online viewers or radio listeners and this covers a very large time period (President Obama’s oath took place shortly after noon and his speech lasted about 20 or so minutes ending shortly before 12:30pm). The amount of Americans who tuned into that segment was decidely larger.

It must have been, because Gallup has releaed a poll indicating that a massive 60% of the nation tuned into all of the address. Do the math and you’ll see there’s a large discrepency between the two numbers.

Original article follows below.

CNN was the ratings winner among cable-news networks during coverage of Tuesday’s inauguration of President Barack Obama, according to data released today by Nielsen.

For the swearing-in ceremony and Inaugural Address in Washington — from noon to 12:30pm — CNN drew 8.5 million total viewers, well ahead of Fox News Channel (5.5 million total viewers) and MSNBC (3.1 million total viewers).

Breaking out the numbers more fully, CNN was also first from 11am to 2pm Tuesday, with 6.9 million viewers, followed by Fox News Channel (4.4 million viewers) and MSNBC (2.6 million viewers). CNN’s numbers are the most ever 11am to 2pm average in its history.

And finally, for the total day of the inauguration — 6am to 3am — CNN placed first with an average of 4.0 million total viewers, with Fox News following in second with 2.5 million viewers and MSNBC in third with 1.7 million viewers.

CNN’s coverage of the Indiana and North Carolina primaries last night topped Fox News and MSNBC, drawing an average audience of 2.65 million viewers from 8 p.m.-11 p.m. ET, 19% stronger than its nearest competitor Fox News. Among the key news demo adults 25-54, the results were even better for CNN. The network drew 1.04 million A25-54, 35% stronger than second place MSNBC and 44% stronger than third place Fox News. Full details after the jump.